i am trying to bond many dsl lines in one network

all modem's are set up with DHCP off and have difrent ISP's
modem's ip is, and

PC have all Static IP from to (with some gaps not 40 ip in line)

10 pc have Gataway dsl 1
10 pc have Gataway dsl 2
20 pc have Gataway dsl 3

With 3 dsl on all working prerfect
The problems start wen i try to add one more dsl (dsl4) on network..
all trafic is frozen and only solution is to turn off-on switch 3
but after some mins the problem is back again..
so far i am working with 3 dsl (1,2,3) and try to found a solution to add 1 or 2 more

Any1 have any ideas or can help plz post

Forgot to mention i dont wanna use a router with wan ports.