Auto Body Works PE cheated and lied to me.

I was transferred to Auto Body Works PE by my car insurance Iwyze for a car accident which my car was involved in. My car was hit by another car whilst standing offside the road, because this happened in less than 6 months of the time with the insurance my access doubled up to R9000 from an access of R4500. I was not happy to hear about this and asked If i could pay this amount in instalments as it was just too much. The panel beater (Auto body Works PE)did not want that as they stipulated that it had to be paid in full. To cut the long story short I generated the amount and on the day of the car being finished and ready for collection, I was ready to pay Auto Body Works PE the full amount of R9000 but the receptionist told me that according to their documents Iwyze covered my access, ofcause just like any happy customer I took off with out asking for proof for this and as far as I was aware panel beaters do not allow cars out unless the full payment is made, on the day of the car collection a checklist was done to show me that everything was installed. A month later I received a call from panel beater saying theres a part which they want to install and that it would take an 1hour and 30 mins. I was confused because as far as my understanding panel beaters don't let the customer receive the car if there's still parts missing. So anyway I sent my car off then an hour later they phoned me and told me that "there is an access of R9000 that I had to pay and as a result they can not release the car to me".. I was absolutely shocked and disturbed by this and immediately phoned my insurance to check this with them. The insurance was also shocked and promised to take the matter further as this was entirely the panel beaters fault and who gave them authority to release the car to me without any access paid. To make matters worse the Panel beater representatives sends an email with my signature fauged saying that I agreed and accepted to the access on the 21st of May 2019 where as I was informed by my insurance Iwyze on the 30th of May what my access amount was. On that document it is only my signature that is written as if signed with finished ink, not clear you can see that its a fauged signature. Ever since then I have been trying to make payment arrangements with the panel beater but they have been giving me the run around promising to contact me. My life has been inconvenienced because of this panel beater. I feel very upset, disappointed and unhappy that my insurer has taken no steps to help me in this matter as they promised to escalate this matter further and also for the fact that a huge company like Auto Body Works could cheat me like this. They don't want to acknowledge the fact that they were at fault and for me to make instalment payment untill the access is paid up. They trapped me and lied to me, if this is how they deal with their mistakes then I'm advising you everyone don't allow your car insurance to send your vehicle to Auto Body Works PE.