Rav 4 1994 - Fob wont disable alarm or immobiliser - Eileen vm

Hi all. I hope someone can help me. Could anyone tell me please how to/or if I can disable the alarm and immobiliser on my car as my fob wont do it. I can open the car door with the key but the alarm keeps going off (driving my neighbours mad) and it wont let me start the engine.

Ive been told by a toyota garage that my particular fob is discontinued. I find this really odd because I would have thought it would have been a simple case of copying it/transferring information to a more modern fob??? Please someone tell me that its not possible for a car manuafacturer to discontinue a fob?

Thanks

Eileen