Advice on repair discounts??

If you are unhappy with their service you need to go talk to the service manager. Go in with an open mind and try not to be an a-hole. Give them an oppurtunity to explain their delays. Then explain what you are unhappy with. Go over the hours they billed you for and what changes could have been made to make the transaction better. Were parts backordered or were they just lazy about the priority of getting your bike done? 9 weeks is stupid though, most turn-arounds should be less than 2 weeks even during the peak summer months.

They may not be able to give you a refund on your bill, but they should offer you some sort of compensation towards your next parts purchase or service work. If they are a decent shop, they should value you as a customer and want to keep your business. When I used to work at a shop, sometimes this would happen and the service manage would maybe offer a free oil change or coupon voucher towards the next service.

The main thing is you just need to go talk to them and explain. Getting into an argument with them will send them into defense mode and they won't do anything. If they are not willing to negotiate or give you the time of day, you should be taking your bike somewhere else.