Gas cylinder exchange games

BP Garage at 273 Durban Rd, Bo Oakdale, Bellville Cape Town, 7530 - Phone ***I recently attempted to exchange 9kg gas cylinders on two occasions, the first time I was told that there was no gas available, while, before asking, I saw that there was.

Gave it another go, only to be informed by the lady on duty that the cage in which the gas is stored cannot be unlocked as the key to the lock was broken.

The impression I get is that gas exchanges are accompanied by great inconvenience, hence the reasons put forward as excuses that it is not possible.