By Joseph Wilkes Santander is offering its customers a chance to win £20,000 if they invest at least £1,000 in their bank account. The high street bank has sent out letters to its account holders, encouraging them to “win” by investing. Santander stated: “Invest at least £1,000 in a Santander Stocks and Shares ISA 2024 to be in with a chance of winning the value of your investment back, up to a maximum of £20,000.” They added that there would be one lucky winner each month during April, May, and June 2024. The bank further clarified: “UK tax residents, 18+ only. New and existing Santander cust…