We had this once and Virgin sent out someone pretty sharpish to join the two ends using a small box and then a week or two later they relayed a new cable because the old one was about 15-20 years old and we had been having picture break-up anyway. That was probably about 10 years ago though.
Paid an engineer - did exactly as I thought - added some compression connectors, female to female connector and we're back up and running. Took all of 10 minutes and everything is running as normal.
Or I could have waited 12 days without any internet for an engineer to come to tell me I need a new cable pulled, which he can't do so I'll have to wait for another team to come and do that. In the meantime he'd apply the same fix I got the engineer to complete.
unless the cut is in a place that cannot be repaired or there is not enough cable to make the joint the tech would have done what you have paid for
compression connectors are the right thing and you may well have got a good job but VM may not be happy if its not as it should be as everyone on the same cab as you could be ringing in with problems - thats the worst case - best case is - all is good - dont cancel the vm tech let him check it and add a waterproof gel box
start with the last point - you are on a domestic connection - it gets fixed when it gets fixed - thats as it is - thats what you signed up for right or wrong - if you want better you need a business line - i agree WFM has changed things but VM and all other isps have not kept up
i also agree 12 days is a long time but again thats as it is - they book the 1st available tech - you can ring and hope for a cancellation but nothing may be available - you did not have to pay all VM repairs are free - you chose to by pass the system so the cost is down to you
why should you not repair it yourself -
1st is against the T & C's - the cable you have repaired is not your property - its on your property but the 2 things are not the same - its expressly said in the T & C's that you cannot modify in any way the cables and boxes - that would cover what you have done - but in fairness from what you have said the engineer you used has done it correctly by using compression ends and its likely that there will not be a problem - yes thats interference back to the cab which can affect all other connections on the cab - again compression connectors will stop that - you could have used screw on or even twisted the 2 ends of the coax together - would not have been the 1st time
so let the tech check it - add a gel box and i'm pretty sure he will be happy