I PURCHASED A JUNKERS BOSCH THERMAL SOLAR PANEL FR...

I PURCHASED A JUNKERS BOSCH THERMAL SOLAR PANEL FROM CLIMANT.
AFTER 3 OR 4 YEARS I CONTACTED THE SERVICE CENTER AS LITTLE HOT WATER WAS GIVEN FROM THE PANEL WITH VERY FEW PRESSURE.
THE PANEL USED THE TOTAL WARRANTY FOR ALL FOR 10 YEARS (WRITTEN ON THE QUOTE). THE CUSTOMER OF THE SERVICE CENTER REFERRED TO ME THAT IN ANY CASE IT WAS NECESSARY TO PAY 40 EURO FOR THE CALL RIGHT AND 35 EURO FOR THE EXIT OF THE TECHNICIAN. THEREFORE, TO HAVE AN APPOINTMENT WITH THE TECHNICIAN, I HAD TO ACCEPT THESE CONDITIONS. THE TECHNICIAN AT THE FIRST APPOINTMENT WAS NOT PRESENTED AS WELL AS IN THE SECOND (WITHOUT NOTICE ALSO). FINALLY AT THE THIRD APPOINTMENT THE TECHNICIAN ARRIVES AND SAYS THAT IT IS NECESSARY TO REPLACE THE TANK FOR AN EXPENSE OF MORE THAN 300 EUR (ONLY FOR THE PURCHASE OF THE TANK) BECAUSE IT WAS TRAINED AND THE 10-YEAR WARRANTY DID NOT COVER THIS EVENT. AFTER VARIOUS PROTESTS, WITH DESPERATION I HAD TO ACCEPT. THE TECHNICIAN REFERRED TO ME THAT IT SHOULD HAVE TO RETURN WITH THE MATERIAL AND THAT I SHOULD HAVE TO PAY 75 EUROS FOR THE RIGHTS ABOVE. I REFUSED TO PAY FOR SAYING THAT I WOULD PAY FOR EVERYTHING AT THE FINISHED WORK. HAVE NEVER BEEN SEEN. SO I CALLED A PRIVATE TECHNICIAN WHO REPAIRED THE PANEL WITH 120 EUROS. THERE WAS NOTHING BETWEEN THE TANK AND THE LIMESTONE.
WHAT TO SAY? YOU FIND THE CONCLUSIONS.