Eh, I think you're overeacted.

After your loan approved, they still need to get an chassis number and update JPJ system. Sometimes the delay can happen due to hiccups on the process flow and not entirely the fault of the sales agent himself. FYI JPJ system also tends to go down quite frequently, causing delays.

1 week to get car after loan approved is reasonable, don't expect to get your car the same day the loan approve la.