False/Misleading Advertising

On the 2nd of June 2020, I bought Mnumzana fencing from Build It, Elliot Street, Mthatha. Measurements were 1.8 * 30m, but it is only 20m in length and unfortunately we couldn't take measurements when we bought it because its sealed and rolled. I bought 4 of these and only 75% of my yard is fenced because of this shortage. When I called the number on the slip, ***, the lady told me it's not their fault but the suppliers. I don't liaise with the supplier I bought from them. I need the 4* 10m that they for their supplier stole