Hi, just went to builders express in Sunward Park to buy some mounting tape I saw advertised

Hi, just went to builders express in Sunward Park to buy some mounting tape I saw advertised. Worst R70 I have ever spent. Each strip is supposed to hold 2kg, the product was Patt x No More Nails mounting tape ten strips per packet. Ihad four strips on a small picture I'm trying to hang. Just keeps falling down 👎. Read and followed the instructions, really fed up.