HTC — Hang problem in htc desire 620g

Address:	125001
Website:	htc.com

Respected sir, I want to file a complaint against HTC company as I had purchased my HTC desire 620g in July end and after 2months only the phone had problem I.e. problem is as when I call someone n cut the call then call doesn't end but it continues .Until I switch off my phone my phone doesn't end the call .secondly, it hangs too much and also I want to convey u that only 3-4apps are downloaded then also it hangs too much .third problem is that sometimes when I open my contacts it displays loading and doesn't open.I had given 3times in HTC centre in hissar but same problem persists and now before 15days also it had been submitted to HTC hisar and they send the device to banglore and now 2days ago I collected my phone bt the problem is same .I m seriously disappointed from HTC care .I m not an idle person that I repeatedly visit HTC I m really frustrated from HTC by visiting again and again and then also problem is not solved.Plz help me out to solve this problem and if possible I want new phone.I m attaching some screenshots of this problem u can see in this that I dialled a call then I cut it but then also call doesn't end u can see the time in call and it doesn't contain any cut option Ki I can cut my phone also if call comes I m unable to talk to the person.so plz help me to solve this problem.