In November 2012, the Information Commissioner's Office (ICO) publicly listed ScottishPower as one of a number of companies that it had concerns about due to unsolicited telephone calls for marketing. The concerns were based on complaints. In response, ScottishPower said that it was working with the ICO to address any issues. In early 2015, Scottish Power was temporarily banned from signing up new customers, due to long-standing and serious concerns regarding poor customer service, overdue bills and failure to implement rulings made by the Energy Ombudsman. The company's failings continued to be highlighted in the press later in the year, with complaints levels 20 times those of their best-performing competitor. In April 2016, Scottish Power released a press release that an £18M agreement had been reached with OFGEM following their investigation into customer service standards. In 2017, Scottish Power created controversy when they pursued a couple for a £4,300 debt despite the couple not owing Scottish Power any money and, moreover, not being customers of the firm. Scottish Power ignored letters from the couple, instead sending bailiffs to the home of the couple. It later transpired that the couple were in no debt to Scottish Power. The Energy Retail division contains ScottishPower Energy Retail Ltd which holds the gas and electricity supply licences. At the end of 2019, this division had 9.2% of the domestic electricity market in Great Britain and 7.9% of the gas market. Customer numbers have fallen by 6% since 2015. Also included in this division is SP Dataserve Ltd which is responsible for the metering and data management work and is the first-ever meter-reading company to allow customers to text in their meter readings. The Energy Networks business contains three asset owning companies SP Transmission Ltd – holds the transmission licence for central and southern Scotland and owns the part of the Moyle Interconnector with Northern Ireland Electricity, SP Distribution Ltd – holds the distribution licence for central and southern Scotland and SP Manweb Plc – holds the distribution licence for North Wales, Merseyside, and Cheshire. A fourth asset management business SP Power Systems Ltd maintains and repairs the distribution networks on behalf of the owners and acts as the distribution network operator. The operation of the transmission grid is carried out by National Grid plc. Energy Wholesale contained two companies ScottishPower Generation Ltd which formerly generated 6,200MW of electricity power in the United Kingdom using coal-fired thermal power stations, combined cycle power stations, hydro-electric schemes, pumped storage generation and were acquired by Drax in 2018. In 2006, ScottishPower Renewables (SPR) was granted permission to build Europe's largest on-shore windfarm.