Have any of you heard of Tech1 Engine Installers in Tampa?

I brought my 90 mustang 5.0 to them last Friday so that they could take the old motor out and put a lower mileage 89 gt motor in. They came with the tow truck, I signed the agreement, and paid a $600 deposit (the cost of the 89 GT motor was $600), it was supposed to be done Monday.

Today is Wednesday, and it's looking like it still won't be done, although this morning I was told it would be today. They said the delay is due to getting the wrong motor mounts twice, and the wrong speedometer cable once (I needed to replace the speedometer cable).

Is this normal? Am I being too anxious here? Any help would be appreciated!