Passat alarm system question

A while ago my remote stop working and I tried to start the car with just the key and the alarm went off. Well I ended up having to get my spare keyless remote and that solved the problem. Is it possible to disarm the alarm with just the key alone? The dealer said that I may have a problem with an alarm sensor in the driver's side door, but they just ripped me off for other repairs. So I am very hesistant to pay for them to look at a problem that they didn't seem 100% sure that I really had a problem. They said that if I had a valet key, that it could disarm the system, so any key could- well I don't have a valet key so I wouldn't know if that's true or not.

Please help, I don't want to get ripped off again.

Thank you

you can set/ disarm the alarm with the driver door key lock. If it does not arm/disarm than you will need a new door latch.

Thanks for the information!