I appreciate that this sort of thing shouldn't happen, but focus on the outcome you want - which I would think is to have you car working properly as quickly as possible. So how about this:
1. Drain the coolant and remove the hose
2. Take the hose to a decent motor factor and get a replacement. Easiest would be a motorsports specialist who could make you up something from silicone sections
3. Fit new hose, refill with coolant, get car back on road
4. Send old pipe to dealer to order a replacement when MMC have got over their current staff shortages
5. When new hose arrives, make an appointment with dealer to fit new pipe
6. Keep old hose and fit temporary pipe as spares
