Nickname Confusion

American's have a habit of standardizing each and everything. That holds true for nicknames also. For e.g. Anthony is commonly addressed as Tony, so is William by Bill. I knew about it but generally did not paid much attention to it.
One fine day two gentlemen named Anthony and William from Ronald O'Mara Engineers visited me for an up-coming project at my workplace, and everything went fine.Now after two-three days this guy Anthony calls me for an update on their proposal. Generally I get useless sales calls throughout the day and I kind of answer them anything rubbish that comes to my mind. So this guy calls and speaks.
Guy: Hi, this is Tony from O'Mara.
At this point I am trying to recall who is this Tony and what the hell is O'Mara!Then he goes
Guy: Bill and myself were wondering when do you want to start the project!!
As off I am still trying to figure-out who is Tony and O'Mara and now who is this Bill?I though this is one of those sales-reps once again disturbing me, So stupidly I answered him the following.
Myself: Well! At present it seems we are not interested in moving forward but shall get back to you as soon as we make a decision!!
So Mr. Tony or lets call him Anthony was quite confused and replied
Tony: Frankly Purvin, we though you wanted to work very quickly on this project and were expecting an answer. Anyways let us know whenever you are ready to move forward. Thanks.
After hanging-up the phone I dig through my files to find out who was calling, to realize its Anthony (Tony) and William (Bill) from Ronald O'Mara Engineering company (O'Mara) guys working on one of our important project!!
Screw Me!!!!!