1. Negotiate with merchants: communicate with merchants and raise concerns about high interest rates. Explain the situation and ask for a lower interest rate. Merchants will be willing to negotiate and offer more reasonable interest rates.

2. Look for other installment options: The merchant does not agree to lower the interest rate, and may consider looking for other options to provide installment payment. Compare the conditions and interest rates of different businesses and choose the installment plan with more reasonable interest rate.

3. Seek third-party financial institutions: Physical stores cannot provide reasonable interest rates, so they can seek financial services provided by third-party financial institutions. Some financial institutions offer installment payment options related to the purchase of consumer goods, and the interest rate is more competitive.

4. Check the contract terms: re-read the signed contract terms to ensure that there are no hidden fees or additional conditions. If you find problems or loopholes in the terms of the contract, you can seek legal advice to understand the rights and interests and feasible legal solutions.

5. Buy in full or choose other methods: If you can't find a satisfactory installment choice, you can consider buying a mobile phone at one time or choosing other purchase methods, such as credit card installment, and make sure to evaluate your financial situation and affordability before making a decision. "Physical store" refers to the commercial retail store that actually exists in the physical space, also known as physical store, physical store or traditional physical store. These shops are located on the street or in the business district, and are carried by actual buildings or shopping centers.