It seems to me that it's actually harder to invent excuses than it is to get a sale.

Value the relationship more than making your quota.

The more a prospective customer clicks on you and your stuff, the easier it is for them to make a buying decision in your favor.

The best way to apologize is to let the customer vent first. Don't interrupt, just take notes and make empathetic noises. You can even tell the customer that it makes you mad too. Second, ask the customer what their speed of need is. Tell them what they ant to hear. That you apologize, that you understand how they feel, that you are meeting with the appropriate people to get a resolve, and that it will be done in 24-hours.

Price is not a consideration when a personal relationship exists.

Once you discover what your attitude is, or isn't, you'll have a starting point and an understanding of how to move forward.

The reason you have to say "Trust me" is that you haven't earned it and are forced to ask for it - BAD MOVE.