When you take your car to the garage for a service for example, they will of course perform standard tests to check that everything is working properly. They may also perform a software update to make sure your car is completely up to date. However, with this software update, any tuning or other software modification(s), will be overwritten. This can be very annoying, however not irreversible. Contact the company where you had your chiptuning performed for their conditions, but almost every professional chiptuner offers the service of reloading the chiptuning software free of charge in such cases, so you can get back on the road again!