Pixellation & picture breakup, assuming you've restarted your box once, indicates there's a fault somewhere that's causing your TV signal to be poor. Netflix & OnDemand services are carried over the internet and so wouldn't be affected by this unless there's slow internet speeds - which would be a different issue.
Sometimes it can help if you can identify any specific channels (including HD/SD?) that are affected, but it will only help expedite rather than alter the end result - that you need to report the fault to VM so they can investigate. It may require an engineer visit or a box-swap, VM's diagnostics can confirm this. It's also no surprise that this is getting worse - whatever the fault is, it needs fixing 🙂
Realistically, you have 2 choices:
You can persist with calling through to TV Faults, they can usually do the necessary diagnostics immediately and then arrange the next steps. Alternatively, you can wait on here where VM Forum staff work through posts and can often assist - but this can take several days.
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