Is it possible for the central locking to be tampered with/ or changed so the keys don't work?

With the correct scan tool, the security system can be reprogrammed and if the original key is present, that would make it even easier.

In the meanwhile, check all the fuses first, especially those under hood. Ensure the brake lights are working. A blown fuse would result in non starting.

They might want to steal your car or wants to sell their services to you, get your car working again for a fee, if this was done delibrately.

Something is definitely wrong here and you need to pursue this with the company further. Get their manager involved as this seems like you could be losing your car in the near future.

The key has a transponder chip inside and if it was removed, you would not be able to start with it.

Was the spare key with them too?
Is spare key a valet key or with transponder?

Spare keys comes in 2 different type, one is a valet key which does not have the transponder and can be used to open doors but you won't be able to start with it. The other would have similar capabilities as your present.

Since the fob is not working, have the fuses checked. There is a possibility the brake light/security fuse is blown and this would affect the security system.

You mean you are able to start with the key you left with them but is not able to operate the keyless entry system?

Did you use the spare key to try starting again?

WE CALL IT "DEVILMENT" 'ROUND MY PARTS!

TRY THE STUFF KHLow2008 SUGGESTED. IT MIGHT JUST BE SOMETHING SIMPLE AND STUPID

BACK IN APRIL OF '84, I TRAVELED FROM HUNTER ARMY AIRFIELD (WHERE I WAS STATIONED)---TO HOME (4 HOURS AWAY). ALONG MY ROUTE HOME, I STOPPED AT FT. JACKSON, S.C. I HAD JUST GRADUATED FROM RANGER SCHOOL, I WAS WEARING MY DRESS UNIFORM PROUDLY DISPLAYING MY RANGER TAB ON MY LEFT SHOULDER

I WAS AT "JACKSON" ONLY TO "STRUT MY STUFF", AROUND OTHER ARMY PERSONEL. BEFORE DOING SO IN MY HOME TOWN, DURING MY 9 DAY PASS (RECOVERY TIME FROM THE H. ELL I HAD JUST BEEN THRU FOR SEVERAL MONTHS

UPON LEAVING THE PX (POST EXCHANGE), IT WAS TIME TO HEAD ON HOME

I JUMPED IN MY JEEP CJ5 AND DROVE 2 MILES OR SO, OUT THE FRONT GATE. THEN I THOUGHT, GOTTA HAVE SOME COUNTRY MUSIC, SO I REACHED DOWN TO TURN ON THE RADIO

. MY DARN RADIO WAS GONE!

.I WAS SOOOOO PIZZED!

I GANDERED AROUND AND NOTICED MY BAGS WERE MISSING TOO!

. MORE PIZZED!

UPON ONE MORE SWEEP WITH MY EYES

.I NOTICED IT WAS SO VERY SIMILAR

BUT THIS WAS NOT MY JEEP!

I TURNED AROUND, DROVE BACK, AND PARKED IT AS CLOSE TO WHERE IT WAS, AS I COULD

GOT IN MINE AND LEFT!

****** MORAL OF THE STORY ******

ARE YOU SURE YOU ARE IN "YOUR" VEHICLE?

COULD IT BE THAT SOMEONE ELSE USING THEIR "WRONG KEY", TRIGGERED SOMETHING SO THAT YOU KEY DOES NOT WORK?

1ST PIC) MY JEEP, MY DOG, AND ME. JUST BEFORE I WENT RANGER SCHOOL

2ND PIC) THIS WAS TAKEN SHORTLY AFTER RANGER SCHOOL AT THE "RANGER BALL"

THE MEDIC