iPhone 4 doesn't work using iOS7

I am feeling completely helpless with my iPhone 4 since upgrading to iOS7.

Here are the list of complaints:

1. iMessage doesn't not send, continuously freezes have to reset phone (this has to happen about 6 times a day)

2. iMesages, emails, whatsapp (basically all form of communication) does not go through for hour (until I happen to reset my phone). MAJOR time leg in recieving imessage also, or messages not being delievered to me at all

3. Phone calls not going through. There have been multiple instances where my phone will be next to me on sound, and I will have missed calls.

4. Phone turing-off and will not turn back on until it decides to (has happened twice, once for 20 minutes the other time an hour)

I made an appointment with Apple, and their response was:

1. There is nothing wrong with the hardware of your phone

2. Have you done a hard reset- my anser: yes multiple times

3. We cannot help you but we can suggest: 1. replacing your phone for $250 (thought it wasn't an hardware issue?) OR 2. You can sign up for a new phone plan and get the iPhone 5 (REALLY?!)

So it seems that Apple has completly forgotten about iPhone 4 users. My phone is a year and a half old, in perfect condition, and now the only solution is to buy a new phone- SHAME Apple. I have always been a dedicated Apple user but after this experience I will definitely be giving other products a GOOD look.

If anyone has a solution please let me know, but I have really done EVERYTHING, to the point even Apple doesn't know what to do.