Black screen on Motorola Krzr k1m

I have the Krzr K1 phone also. After I had the phone for 3 months it would not keep a charge. I took it to Verizon & they exchanged the battery, the girl there said they always have problems with that size battery. After about another 6 months, I had to go & get another battery (this time there was a charge). Now about 10 months later my phone starting to not charge the battery. Sometimes it says invalid device (or something like that). Now my screen is totally black. Most of the time I can make & receive calls, but I do not know who is calling since there is nothing but black on the screen. Sometimes it will tell me it is not a valid number, this seems to be happening more & more frequently. Thankfully I can get another phone next month. Do not buy this phone, it is a piece of junk. Jan