Pixellation is (more often than not) a symptom of poor TV signal. Streaming apps & OnDemand are carried over the internet and so wouldn't be affected. The stock answer is to reboot your box once, then report your fault.
I'm also sorry to say that VM's call queues are quite high at the moment, for numerous reasons. There isn't a magic wand to that either, otherwise everyone would be waving it! You can try using the text message service (07533 051809) but it'll take a day or so to respond, it's not instant.
Not sure which box you have or are asking about - check here - the TiVo & V6 both run TiVo software, the V360 is a whole new platform and (although opinions vary) is certainly in its infancy compared with TiVo/V6. Regardless, pixellation is almost certainly a signal fault which has nothing to do with which box you have.
You are likely to need either a replacement box or an engineer visit.
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