Suspended from SFP as RM delivered late - Advice

Hi, we have just had our SFP privileges suspended due to a drop in on time delivery performance.
This was due to 7 Saturday collection items being processed and delivered late by RM, they should have been processed Saturday for delivery Monday, however the items were all delivered Tuesday, so probably just dumped somewhere and left till Monday morning.
I have emailed my collections manager and await a response.
Just wanted some advice on an action plan to get SFP re-instated, its a tough one because its not our fault (although Amazon don’t really care about that), and the answer how do you prevent this from happening again is…Don’t use Royal Mail and deliver the items myself

Any help or advice would be appreciated and also has this happened to anyone else.
Oh and as a side note spoke to SS before the actual suspension and they said not to worry as my account looked fine???

Thank you for reading.