Fedhealth Lost Critical customer data

It's almost time to submit tax returns. Fedhealth has sent the Tax certificate for the time after the merge with Topmed, but not the 5 months of the same tax year before the merge. Topmed is no longer a thing so I can't get it from them. When I ask fedhealth to send it to me, they tell me that they only have record of the 2018/2019 tax year. How is that supposed to help me? How do I submit This to SARS if I can't get it from the company that merged with the company that had it.. Honestly, I think they lost the data and now don't want to admit it.