Damages but refusing to pay out despite having paid for insurance

We had great service from when we asked for a quote up until they day of packing. But then the movers came unprepared, didn't have enough boxes so had to start using our plastic crates, ran out of time and started carelessly stuffing valuables into already full boxes, and they didn't have a pulley or trolley to move the piano which was part of the quote. When the ship was already docked in London, we were asked for more money as the rand had taken a dip against the dollar. We didn't have the money but it's in the T&Cs if you read carefully, so we paid. Upon delivery we realised that a big amount of items had been damaged or broken, including the piano. Luckily we oped for 3.5% Comprehensive Insurance and we paid and extra R23k for insurance. I reported the damages to SA Relocations, and that's where the trouble really began. First I had no response, then I was referred to "claims" (no name), who I had to keep mailing until I got a response from the person, surname unknown, who'd also been handling accounts. After trying to get a claims number or process update for a week, we were assured that the claim had been sent to the insurer and everything was fine. We tried to follow up for another month and finally another person responded, saying there's a form we didn't complete and they can't process the claim without us proving that we'd sent it upon packing. Surely they should've done due diligence and ensured that they'd gotten all the necessary forms? They happily took our R23,500 extra for insurance but now shrug and say sorry, that's not valid. It's ongoing but I'm heartbroken over my piano.