Wheelchair repairs: go back and back

CE Mobility did repairs on my wheelchair in April 2021. The bearings they replaced were bigger that the original size. Now, (Dec 2022) the "new" bearings broke completely. My son-in-law replaced the "new" with the "old". I received my wheelchair in 2015. The labour has to be paid cash, which is ±R450. How can one put bearings in wheels which is not the correct size? Or does one have to go back more than once for a proper service delivery which should have happed the first-time round? And at the of the day, only labour will cost you more than R1000.00 if you have to go back and back and back!!