Why different contract details and billing faults all the time with no solutions?

I don't know when VM became this terrible, I never had any issues whatsoever until this year.

I upgraded my package in February via the Upgrade button in my online account. Same day I was sent a contract summary sheet that contained exactly what I ordered - M250 at £34 and Sky Sports plus TNT sports package at £28.75 on Stream, totalling £62.75 pm. That would have been cheaper for me than adding those Flex services separately. Why then did I get an email 3 days later showing the contract I signed up for was for broadband only at £73 and no add-ons? I called repeatedly and eventually (frustratingly) was able to speak to AN ACTUAL HUMAN BEING! Explained the issue and somehow the call cut, so then had to endure the whole process again, repeatedly explaining the issue. Somehow they have no visibility of packages one could upgrade to via one's online account, as the person I spoke to said that that offer was not available. I told them the contract summary sheet number which they checked and agreed to. After almost half an hour waiting on the line for them to speak to a manager, they said the only way they could give me the same package was by still going by the new contract of £73 broadband only (which was now in effect), and they would add the add-ons I had ordered, but they would also add in a discount calculated so I only pay £62.75 monthly which was the original contract I agreed to. I asked if there would be any issues and I was assured there would be none, and even if there was, I could call back and quote the discount reference which they gave. 

Well, fast forward a week later and I get a bill of £83.98 for March. I assumed it was probably because I changed tarriffs mid-package, to account for time on the old contract. I decided to wait until April, and then was billed £72.65. I called and after a long hide and seek with the automated response machine, had to endure explaining everything all over again to someone, eventually they said it was billing irregularities and I should get the credit back the next month, as it seemed I had been overcharged. Why then did I get the same bill of £72.65 for May and June? I decided all the time spent trying to get to speak to an actual human, and having to explain everything ALL OVER AGAIN, was not worth the £10 extra I am being billed each month. It meant I would then have been overcharged by at least £180 over the duration of the contract, but I just could not get myself to get back to call customer service as it is a very horrendous experience! 

I decided last week to add an 02 sim so I could get Volt benefits. It meant that I had to upgrade my  package again, which I saw to be cheaper overall to be honest, and I once again put the order through online. I clearly didn't learn my lesson the first time, as again, contract summary sheet said the same thing I ordered on the day, but the actual contract that came later yet again quoted a different figure, with yet again no add-ons. I now have Volt benefits, but somehow, they "noticed" I had left my 02 contract, the same one I literally just signed up to!! the sim of which I am still expecting!!! You just have to laugh at  how ridiculous this all is. I chose not to bother calling again.

I have decided I will see this contract through, and will NEVER use Virgin Media again after it expires nor will I recommend it to anyone ever again, which I used to do as, to be honest I never had issues with the broadband connection itself.

I have also now concluded that billing with VM is now no longer straight-forward, just so customers can be confused and overcharged, because why did it use to be that you get billed the month ahead for example July 1-31, but now on my bill I saw 21 Feb to 30 April the first month, then 28 Feb (Feb again) to May 31 the next, and then middle of April to end of June the next, like why so much confusion?!!