old ATT plan

I have an old AT&T plan from before they went to Cingular. I have 1000 anytime minutes plus 3 phones on the plan and it costs me $39.99+9.99+9.99=about $60 per month. Even with taxes I come in under $70 per month. I called AT&T this morning as I want to add another line for my daughter to the plan. They are telling me I can't add to this plan as it is too old and I need to upgrade to a newer plan. They have been trying to get me to drop this plan for a long time as they can't come close to it anymore. Closest they have is 700 minutes plus 2 additional lines for a total of 4 that will cost me $90 per month. Basically, I'm losing about a 3rd of my minutes but yet the price will go UP by half of what I pay now. Even if they would let me add the line to my old plan, my monthly bill would only jump to $70 per month so I would come out $20 cheaper than the new plan plus have 300 more anytime minutes. Anyone know if you can still add to an old plan like mine or are they telling me the truth about needing to upgrade? For some reason, I feel I am being fed a line of crap as they have wanted my current plan discontinued for quite some time. Any insite?

This was one of their old local plans. Now they are national plans where the one I have was good for Il.,Wi., and In. I really don't want to take advantage of one of their new promotions. I just want to add another line to my plan. They did this for me 2 years ago when I added my sons line and they were Cingular at the time.

I have had this same experience with AT&T twice in the past, once before the before they went to Cingular and the last time just after the merger.

The first time I wanted to add texting to my existing plan and they made me "upgrade" to a new plan because the plan I was on was grandfathered in.

The second time was after I got married and wanted to add an additional line for my wife, they said my plan had been grandfathered in and I would have to switch to one of their family plans to add an additional line.