Bad experience with Alitalia

I booked flight tickets from Rome to Venice for April 2020, I couldn't travel any longer due to Covid 19 lock down restrictions. I tried many times to claim my refund from AlItalia without any success, the proof of payment was submitted in 2020 and the refund was approved in principle but no funds have been transferred thus far. Calling and emailing the company has not helped. The company owes me over £400. I would not reccomend AlItalia because of my bad experience.