Hi there Catlove,
I am sorry to hear of your troubles.
From your post, it seems like you are having broadband reliability problems (I too have had these), although you are a little light on details.
Unfortunately, similarly to Adduxi, I am sad to say that it is not a good strategy to call in to VM's contact centres, and agree to extending service provision in the hope that the service is fixed. Agreement to extending your services does not guarantee a fix to ongoing issues, should you have these. (I do understand your well-meaning intention in doing that of course.)
Rather, I recommend you do the following:
Step 1: Testing and Diagnostics
Follow the tests I undertook and posted about, in this thread here. You can ignore tests 1 and 2 -- in retrospect, I should not have bothered with those, as they are of limited usefulness. Do try to do all the other ones though. I accept that it's a fair amount of work, but it can help you get some assistance from some of the more experienced people on this forum, including VM colleagues. If you post any screenshots, be sure to omit/redact any IP address or MAC address information.
The benefit of pursuing help on here, although it involves a lot of work, time investment, and self-learning, is that you can minimise your VM call-centre interactions, the results of which can be inconsistent. You will also learn more about your connection generally.
Step 2: Follow a "Broadband Outage Strategy"
A concurrent step is to implement what I call a "broadband outage strategy". I have outlined what I feel is the best strategy in this post here. In a nutshell, the strategy sets out a first step of "piggy-backing" off your mobile phone's (i.e., your smartphone's) data provision in the short term, then moving to a SIM-equippable router, reporting the problem(s) and waiting for a fix, and then if all else fails, "jumping ship" (as ultimately, in 2025, most of us need reliable broadband).
I hope my post is helpful to you, and best of fortune in getting a solution to your broadband reliability issues.