[neilv]

You can ask customer service for help politely and constructively, without disingenuously (or passive-aggressively) stating that the problem is your fault.

If you want, you can acknowledge how you tried to fix it and failed (if that's accurate). But don't say that the problem is your fault unless it is.

(There are situations in which taking blame for a situation not necessarily yours might be a convention, but mistakes of vendors when talking with the vendor aren't one of them, IMHO. For example, you might take a little heat for colleagues, when appropriate, and all the CEO you're talking with needs to hear right then is, "Sorry, I don't have that for you yet; let me get that to you later today." Not "I've been pestering Bob since Monday for the dependency." Then you can go tell Bob that you two really need to solve this in the next couple hours. And if there's a larger problem, like Bob has been overextended by a family problem, or tasking has been unclear since a tentative pivot, then work it with management in the appropriate vertices of the org chart.)