phone freeze and warrenty issue

[schiehallion]

Hi ABers.
I renewed my Orange contract with Phones 4 u at the end of August past and upgraded my Phone to a Sony Experia 10. All went well till the begining of April when it started to freeze then reboot itself in a constant cycle. I took it to Phones 4 u who said that they would normaly send it to a car phone ware house outlet near to where i live to have it looked at. As i live 5 mins away from that outlet i took it there and they upgraded the software. The phone worked ok for a week then the issue returned, so off again to P4U who then sent my phone to the manufactures certified workshop. 14 days later my phone was returned supposedly repaired. I had it back 1 hour and the fault returned. I retured to P4U where they decided it was a Sim card issue and a new sim card was duly fitted in phone. this time the phone lasted 2 days then the problem returned. Back again to P4U who sent it back to the manufactures certified workshop. 5 days later i recieved a call saying the phone is being returned un repaired as there is an issue with the USB port and the phone is out of warranty. I have been on the Sony web site and they say their phones have a 2 yr manufactures guarentee. The USB port on the phone is also the charging port and i have never used this port exept for charging and it always worked. I have heard this freezing issue is a common thing with this phone and i am wondering if i am being fobbed off. Can anyone give me any info as to where i stand on this issue.
Thanks.
John. ps i will be posting this on the tech site as well in case anyone there has had the same freezing issue and can help with a solution.