If your DSL connection keeps dropping I would first check to make sure the wires are connected properly and look out in your NID box outside and see if the wires are not corroded.
Also take your DSL modem outside and plug it directly into the NID box on the customer side and if it stays connected then the problem is either with your inside wiring or your telephone connection plugs inside the house.
If the DSL connection keeps dropping then it's something on the ISP side that they need to fix or it could be the modem.
I once had an issue with my DSL connection dropping and finally they came out and replaced something inside the telephone central office which I assume either a network switch or a DSLAM.
Sometimes you have to keep on contacting the ISP to get them to do something or send a technician out.
If it's raining out then you might have corroded connections that are getting wet and causing a short which causes the connection to drop.