Dear :

Thank you for the enjoyable visit to your plant. [name] and I appreciate the time you gave to us on such short notice.

As we discussed, we are going to deal with the problems you are encountering with the products you purchased from us. We anticipate that, after a thorough investigation, our engineers will shortly find a solution.

Thanks again for the time and hospitality.

Sincerely yours,

[name]

[title]