Huawei 7 no of rings keep changing

[Android Central Question]

I am ready to throw this phone in bin my Huawei 7 rings keep reverting back to 2 and 5 sec rings even when i have changed it back to 30sec rings many times therefore if i am not in vacinity of ph when someone rings and i get message missed calls, also find that my screen is freezing and have to reboot a number of time. Have i got a bad phone??