I once worked very hard getting a shidduch off the ground. It was a tricky situation so I initially spoke to a close relative, instead of the parents. Somehow others got involved, so, when I never got any acknowledgement from the parents, I assumed they just never knew about my involvement.
Well, after a few years that no child was born to the couple, I said to my spouse “I am hereby mochel the shadchanus belev sholem”. Not that I ever had a hakpada, but, in case my not being mochel them out loud was a problem, I wanted to clear it up.
Of course, you can guess the happy ending.
So this is not a bubbeh maaseh, but a first-hand account, from my side, anyhow.
OP, I am glad you got paid, I hope it was adequate! Just in case, please say so!