Deliveroo are responsible for the data you give them. If they fuck up and allow unauthorized people access to that data, they're in breech of the GDPR.
If they haven't informed ICO (and equivalent in any country within GDPR rules) within 72 hours of each breech, they're in even deeper shit. First, they have to be clear about the scale of the breech and what exactly has gone wrong. They've got to be able to demonstrate the steps they've taken to mitigate the issue and prevent it happening in future. If people are complaining on a regular basis for months, they've not done that.