Refusing the Bottle

When does the training end? My son who is now 8 months won't take the bottle. I first introduced the bottle at 3 weeks, but for the last few months I have been exclusively breastfeeding, because my supply was going down and It was just easier to breastfeed then to pump. Now he'll take a sip and then stop, push the bottle away fuss. I'm worried because I'm starting to wean him, he doesn't even take formula. So here's my plan start with feeding bottle once a day, which he used to take with just breastmilk...worked so I moved onto 75% breastmilk and 25% formula. So it's been a few days and usually will only take an ounce or 2 then stop. So do I feed him solids or withold until he drinks more? I've been mixing it into his food.
My mother in law tries, my husband tries and I hide. Its more work then just feeding him, but I have to do it sometime. It's exhausting, but he knows what he likes and won't budge. So I'll just keep doing the same thing everyday until he takes it.