HTC 1 M8 on O2 not receiving calls?

[EezoUK]

So I've had my M8 since launch, it's been a great phone until the last couple of months. I will have a full signal but people randomly cannot connect to me. I've tested this myself by looking at my phone with full signal and calling it from my land line but it will go immediately to VM, I can call it again ten seconds later and it works, seems totally random.

I've replaced the sim card and sent the phone back to O2 for repair who just claim there is no fault, I'm at my whits end with this as I use it for work and it's causing me serious issues. Sometimes I cannot make calls either in he same fashion.

Any suggestions?

 

[VidJunky]

Are you using some kind of Power Saver app? While I have not heard of any that would disable calling to conserve battery, I am not versed on every single one of them. I'm not sure what the cell tower update code/number is in the UK, I here in the US *228 and I think it works for most carriers. You may also ask O2 if they are working on any towers in your area. They could be updating them and causing random overloads of the system while one is down. Beyond that if possible I would take it into a service center, here it would be just about every Corp. store, and make calls until they saw the problem. Chances are if you just sent it in with an explanation they made one or two calls that went through and checked your signal strength and shipped it back to you. IMO.

 

[EezoUK]

No power save apps installed. I'll try tataking it into the store as they seem useless when I ring in.