YES, I have a problem with phone numbers now. When I call France and they want my phone number I cannot say the house number in two digits at a time, I don't 'know' it like that, so I have to go and look at it where I wrote it down in BIG writing so that I can see it sans lunettes. It's the only way I can do it, really. I was OK going back to the english way of dealing with numbers, probably because I always worked with numbers and we would have to read them out that often when checking stuff that that came quite naturally.
When I call France and if there are too many soixante dix septs and quatre vingt dix neufs, I'll say the number back ONE letter at a time. That way, me and the person at the other end are sure. I much prefer the way the Suisse and Beligians say their numbers, much more pratique.
The good thing about franglais and the argot is that when people read it, and they don't know it they should look it up, it will expand there vocabularly no end. The only thing is, and I don't know about Chancer, but I do not usually (well maybe sometimes ) use les gros mots that I know on here, and maybe Chancer is a nicer person than I am and doesn't even know them..
Sometimes I think that I know far more swear words and insults in french than I do in english. NOT that I use them, but unless my lips start moving when I think (I hope not), I just think them a lot of the time when appropriate situations merit them!