C & A Foreign Transmissions

I took my pickup truck to C&A Foreign Transmission for them to check my transmission because it was making some kind of pinging noise. They were the one's who originally rebuilt my transmission. When I took it to them my water pump was about to go out. So the owner called me and said he would fix the water pump for $400 I agreed to let him fix it. That first phone call was on 01/**/14 and then on 01/**/14 I received a call from C&A saying my bill was $668 plus change. They took it upon them selves to do some additional work on my truck without my permission. When I tried to argue my point of me not giving them permission to fix any additional items they refuse to accept the $400 they originally quoted and refused to give me my truck. Until I paid them the $668 plus change for the additional items they were not authorized to fix in the first place. I feel very strongly about this matter. If they wanted to fix something else on my vehicle I should have gotten a phone call from them explaining what those things were before they took it upon themselves to fix it. After everything else they never even looked at my transmission its still making the same noise I originally brought it in for.