Buy some bricks, ready-mixed mortar, a bucket and a trowel. You could do it yourself in less time than you'd spend getting quotes, making tea and otherwise fannying about.
Exactly! I'm no bricklayer, but years ago, I needed a door bricked up, and an alternative door opened up. As the bricks were bare, and on show, I opted to tooth the bricks in properly, and use original matching bricks, from my store, plus what came out from the opened up new door. I would challenge anyone, to spot where in the wall, the door used to be. It wasn't difficult, it only needed a bit of straight timber, to properly align it, as I built.