Seat Altea 1.6 - Security Code Engine ECU - Liz F

I bought my car second hand in a private sale two years ago it is a 2009 . But only one key came with the car . I decided to get a spare key , took it to the dealer who struggled to code a key, Then after many attempts there was an error message on my dash saying safe . Any way the dealer said it needed a new dash control panel which i agreed to , but they cannot code this to the engine ecu . Now after weeks in the garage its been decided that the security code has been removed from my engine ECU , the garage are waiting on further advice from Seat Technical , but i spoke to the garage technician who says he can put the car back to the way it was with the original control panel but i wont have a spare key and goodness only knows what they'll charge me as my quote was to replace the control panel .

It seems to imply that the safe message means nothing as the security is out of the car , does this mean that the spare key which they have willl work as it doesnt have to be coded. Any advice would be appreciated as my car is low mileage and no mechanical problems , all i wanted was a spare key , Thanks Liz